I woke up to about a 12" puddle of oil this morning. Upon inspection it looks like it's leaking from where the driveshaft meets the transmission. In this pic, I've cleaned off all the oil, but the arrow points to where it appeared the source was. Is there a seal behind this? I have to replace the boots anyways, but figured that housed grease in these IRS ends and replacing the boots wouldn't sole this oil leak. Thoughts?

Perfect! Thank you. I cleaned everything off and just returned from a 15 minute jaunt down the freeway so I can confirm the leak point. Of course nothing is leaking now, which makes me think I should check the hypoid level . Is this a job worth tackling without the specialized tools? I see some used makeshift PVC and other tools with various levels of success._________________1970 Westfalia Campmobile - SF Bay Area
https://www.instagram.com/campishome/

About the only specialized tool you need is a tool to pop the seal out and a pair of duckbill snapring pliers. You can improvise if you want but a seal puller will save a lot of aggravation and doesn't cost much. Some pullers are pretty junky though so buy with care.

These seals can weep for years hurting little, as I suggested above you should consider doing other work at the same time that requires having the axle removed to do.

Don't drain the fluid until both sides are complete. You want the fluid to flow out of the junction so debris has a harder time finding its way in. Once you've done all your work (both sides) then consider draining or topping off to complete the job.

Like the posters above say, your output flange sealing surface should be groove-less and shiny clean.

When reinstalling the circlip, make sure that it fully seats; no sense in having the flange pop off down the road somewhere.

Robbie_________________Three rules of troubleshooting:
1. Do the easiest thing first.
2. Don't rely on the guy before you. He was not able to fix the problem.
3. 90% of problems are between the driver's seat and the steering wheel.

I was more interested in the side of that area. (you may want to clean it up first)

Okay, here are pics of the snouts. The wear lines are faint and hard to feel.
Left:

Right:

Also, when I pulled the right drive flange out (I have them just placed in there just to keep them covered) I'm guessing this that I found on the ground is the thrust/spring ring? I haven't pulled the final seal out yet so wasn't expected to see this ring quite yet.

The ring is responsible for the marks on the ends of the snouts so you can figure out where they came from by that.

While you await the new seals shine up the seal areas on those flanges with steel wool or super fine sand paper so they are like a mirror and smooth as a baby's ass._________________Rust NEVER sleeps and stock never goes out of style.

On my transmission the oil leaked because the bearing was a little loose and the splined shaft could move from side to side a little and let oil pass the seal at speed.
I suspect this was from when the transmission was reconditioned and it was not exactly set correctly.
I tightened the side plate maybe a millimetre of rotation and replaced the seals and it has not leaked since._________________Ancient vehicles and vessels

Finished. Not the funnest, cleanest or exciting project. Hardest part was getting the seal to seat. I used the 46mm socket and mallet, but realized after I was done I could have put a bolt/washer/nut thru it and used it as a press.

For the benefit of others tackling this in the future, here are a few photos...